We have to get this out of the way, so for the first post let’s explore the definition of whiskey.
Whiskey is a distilled liquor made from grains. Any grain can be used, and the most commonly used grains are barley, corn, rye, and wheat. The one characteristic of whiskey that sets it apart from other distilled liquors made from grain (like vodka) is that the taste characteristics of the grain are kept and sought after. Whiskey is distilled at less than pure alcohol levels so that the flavor components of the mash are passed on to the end product.
Vodka is also many times distilled from grain (grain alcohol,) but vodka is a neutral spirit which means it is distilled to produce a product that is pure alcohol (and then later cut with water) so that all of the flavor are removed.
It is the flavors of the grain that makes a grain alcohol whiskey.
Some examples of whiskey are bourbon, rye, Canadian, moonshine (if made from grains,) Scotch, and Irish Whiskey.